analysis of their density and distribution. The following accounts 
should thus be considered open to serious question, but are the "best 
guess" at the present time. 
Leach Petrel (Oceanodroma leucorhoa ): 380 * Fifteen percent of 
all birds identified as this species belonged to the dark-rumped form 
(Soccorro Petrel). The species as a whole was most abundant in coastal 
waters near their breeding islands, but individuals were found scattered 
throughout the entire area. Soccorro Petrels had a second area of 
concentration from 03°S to 15°N along Longitude 097-5°W. A large number 
( 85 +) of "white-rumped storm petrels" in this latter area may have been this 
species or might have been Galapagos Petrels ( Oceanodroma tethys ) or 
Harocurt Petrels ( Oceanodroma castro ). 
Harcourt Petrel ( Oceanodroma castro ): b6. Apparently most abundant 
in the South Equatorial Current, but probably present in small numbers 
at least to 10°N. The collection of one specimen at 00°5^ ,f N by 097°3I I W 
confirms their presence in this area. 
Sooty Petrel ( Oceanodroma markhami ): 9* These birds were observed 
only along Longitude 097*5°W between 07° and 13*5°W. In color and shape 
they appeared identical to Soccorro Petrels, but their flight pattern 
was more erratic and they were almost twice as large. 
Ashy Petrel (Oceanodroma homochroa ): 31* Found only in coastal 
waters off of central Baja California. 
Black-Petrel ( Loomelania melania ): 36 . Coastal waters of Baja 
California and Mexico from 20° to 25°N. 
Least Petrel ( Halocyptena microsoma ): 9- Most abundant in the 
general area of Guadalupe Island, although two birds were found at sea 
between 12 . 6 ° and 15 . 7 °N. 
Wilson/Elliot Petrel ( Oceanites oceanicus/gracilis ): b. All found 
within the warmer western waters of the South Equatorial Current. 
White-throated Letrel ( Wesofregetta albigularis ): 33* Found 
throughout the South Equatorial Current, but most abundant in the colder 
eastern area. 
White-bellied Petrel ( Fregetta grallaria ): 1. This bird had a 
well defined dark throat and pure white belly. It was observed at- 
01°42 f ]Sr by 104° 41* W. 
White-faced Petrel ( Pelagodroma marina ): 1?. One brief sighting 
of a bird which might have been this species occurred at 07°l6 1 N by 
n 8 ° 3 i f w. 
